Thursday, 5 March 2015

1. State gauss law for the electric and magnetic fields. Derive its integral and differential forms. Make at least two conclusions

2. A positive charge Qv c/m3 occupies the volume of a sphere. At a point in the interior at a distance of r from the centre, a small probe of charge of +q is inserted. What is the force acting on the probe charge?

3. State ampere’s force law. How it is different from coulombs law?

4. Explain the tracing of a charged particle motion in x-y plane, in the region of crossed electric field B=B0 az.Assume that the charge q having mass m start at t=0 at that point with initial velocity v= vx ax + vyoay.What is the result for B0 = 0?

5. Prove that divergence of a curl of avector is zero,using stokes theorem

6. A magnetic field H= 3 cosx ax+z cosx ay,A/m for z0

= 0 for z<0

is applied to a perfectly conducting surface in xy plane. Find the current density on the conductor surface

7. Let A=5 ax and B= 4 ax+ By. Find by such that, angle between A and B is 45. If B also has a term Bz az, what relationship must exist between by By and Bz

8. A uniform line charge =25 nc/m lies on the line, x=-3m and y=4m, in free space. Find the electric field intensity at a point(2,3,15)m

9. Two small identical conducting sphere have charges of 2nc and -1nc respectively. When they are separated by 4cm apart, find the magnitude of the force between them. If they are brought into contacts and then again separated by 4cm, find the force between them

10. Obtain the expressions for D and E using gauss’s law

Unit-2

1. Derive the expression for coefficient of coupling in terms of mutual and self inductances

2. An iron ring with a cross sectioned of 3 cm2 and a mean circumference of 15 cm is wound with 250 turns wire carrying a current of 0.3A. The relative permeability of the ring is 1500. Calculate the flux established in the ring

3. Obtain the expressions for D and E using Gauss’s law

4. Write short notes on faradays laws of electromagnetic induction

5. Derive the electrostatic boundary conditions at the interface of two dielectric media. If one of the medium is conductor, discuss the field pattern